[PATCH] cat.py: fix Python deprecation warning

[Scott Kostyshak]

See attached patch regarding our development script cat.py. It fixes a
Python 3 deprecation warning. However, I believe it changes behavior
with Python 2. The script has a "python3" shebang line (see
3f03f0a447e), however that does not mean that it is not currently
compatible with Python 2. Should I add a version check? i.e., use mode
"rU" if Python 2, and mode "r" if Python 3?

Scott
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-cat.py-fix-Python-deprecation-warning.patch
Type: text/x-diff
Size: 1516 bytes
Desc: not available
URL: <http://lists.lyx.org/pipermail/lyx-devel/attachments/20200319/78603f9b/attachment.patch>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: not available
URL: <http://lists.lyx.org/pipermail/lyx-devel/attachments/20200319/78603f9b/attachment.asc>